yeah, hes not even close to Raul, but i havent seen anyone say that either. probably missed those posts
yep, messi is a few realms under him, Cassano (Roma) level at best

. but seriously, you cant compare players from different eras so easily. you have to take all factors into consideration. the strength of the era (Del Pieros > Messis), the strength of the league (DPs > Messis), the strength of your team compared to other teams of that era (Barcelona /and Spain, which shows what a team Messi had around him/ 2008-2012 was too strong for any other team of that time), the quality of other great players from your era (again. DPs era > Messis), the style of play your team uses and the teams use against you (DP had it much harder), the number of great teams/rivals you had (DPs > Messis) etc. ofcourse, if you look at stats only, Messis career seems more impressive, but thats not the way players should be compared. in fact, there is no way we can compare them, there can only be preferences and opinions on who is better/greater/whatever.
heres a thought for example, imagine Del Piero in the 2008-20012 Barcelona instead of Messi, and see the result (IMO DP still wouldnt score as much as Messi, simply because he plays differently, but i think they wouldnt lose to Inter 2010 and Chelsea 2012 with DP-Etoo/Ibra/Villa upfront, also that 2012 classico had Del Piero written all over it, hes the type of player to decide such games). also try to imagine messi in any Juve team (Lippis, Capellos, Serie B, post Calciopoli) Del Piero played in.
taking the factors into consideration i mentioned above, Del Piero is definitely the better football player to me, but Messi achieved more (individually) due to given circumstances, not superiority in talent/quality.